In vitro Establishment of Native Yerba Mate (Ilex paraguariensis A. St.-Hil.) from Uruguay

Abstract

Yerba mate (Ilex paraguariensis A. St.-Hil.) is a species of great social and cultural importance in Uruguay, with outstanding medicinal properties. Although there are no commercial plantations in Uruguay, there are natural populations that represent a reservoir of genetic diversity for the species. The propagation of yerba mate is a limitation that must be solved to make possible any productive or conservationist activity of this genetic resource. In vitro culture techniques allow the production of a large number of relatively uniform plants from little starting plant material, resulting in a larger genetic gain. The initial stage of in vitro establishment is limiting for cloning, since there is generally a high percentage of losses due to contamination and oxidation of the explants. In this work the response of native yerba mate materials from Gruta de los Helechos (Tacuarembó, Uruguay) during the in vitro establishment stage was studied and compared with commercial plant material The effect of two immersion times in sodium hypochlorite (15 and 20 minutes) and the effect of adding silver nitrate to the culture medium in two concentra-tions (6 or 12 µM) were evaluated. The addition of silver nitrate to the culture medium reduced bacterial contamination and oxidation of the explants regardless of the concentration used. Seventy percent of the explants of native I. paraguariensis survived the in vitro establishment stage and new shoots developed from axillary buds.